The invention relates to the fifth wheel bearing plate improvements, and more particularly to fifth wheels with an antifriction plastic liner.
There are now in operation hundred of millions of trucks going back and forth all over the world doing over 75% of the material land transportation, the rest of 25% being covered by the rail, aircraft and other systems.
The fifth wheel is using grease at a rate of about 1 kg per 3 months depending on conditions. This grease is in danger to be contaminated with dirt, dust, and other particulate contaminants normally associated with travelling long distances sometimes in areas with much dust and sand. Consequently this grease is becoming an abrasive paste, and because of the special additives for pressure and water repellency, this paste is glued to the bearing surfaces of the fifth wheel, as well as on the surrounding areas.
When the time is coming to clean it is necessary to use high pressure steam, and the regreasing operation is per se complicated and time consuming.
A serious effect is the environmental pollution by which millions of tonnes of used grease is discharged in the environment or in the treatment facilities at the truck maintenance centres around the world.